An autostereoscopic, or 3D, display allows a viewer to see a view with depth by providing a left image and a right image to the viewer's corresponding eyes. In the past a number of displaying devices for 3D viewing have been disclosed, notably those by Eichenlaub. U.S. Pat. No. 4,717,949 (EICHENLAUB) discloses an autostereoscopic display having light emitting lines for illumination, and a light valve for image display; U.S. Pat. No. 5,311,220 (EICHENLAUB) discloses an autostereoscopic display having a transmissive display alternately displaying right and left images and a light generating/transmitting surface which has emitting regions alternately flashing on and off for separately illuminating the right and left images displayed at different times.
All these autostereoscopic displays cannot be easily converted to a regular image display so that the same display device can be used both for 2D viewing and 3D viewing.